We have a policies page on our site:
http://www.graphicd-signs.com/client-policies . The sidebar also explains our policies.
It takes pressure off of us; we direct people to it if they have any questions about it.
Regarding printing, we bill in full before sending a job out; logos are 2/3 upfront, web is 1/3 installments, with 1/3 up front. And minor edits are billed in advance, 100% up front.
So, one suggestion is to actually PUBLISH your policies - therefor, it seems less selective for everyone - as in - here's our company polices for everyone (so it doesnt look like they are being singled out).